Construction of a nano dispersed Cr/Fe-polycrystalline sensor via high-energy mechanochemistry for simultaneous electrochemical determination of dopamine and uric acid

A bimetallic polycrystalline sensor (Cr/Fe-SNCM) having nanosized and high dispersion was designed and used for the electrochemical simultaneous determination of dopamine (DA) and uric acid (UA). Catalytic nanosized Cr/Fe were highly anchored on N/S/O-contained porous carbon with high dispersion and polycrystalline Cr/Fe via energetic mechanochemical method and high-temperature carbonization. The obtained Cr/Fe-SNCM exhibited high graphitized carbon supporter and endowed high electron transport and signal output for the whole sensor. Moreover, highly dispersed Cr/Fe sites and the polycrystalline form (metal-N/S/O) efficiently enhanced the catalytic reaction, leading to a limits of detection (based on the 3 sigma/m criterion) of 25.8 and 22.5 nM for DA and UA, respectively. This is 1-2 orders of magnitude lower than many state-of-the-art reported sensors. The Cr/Fe-SNCM1.0 sensor exhibited wide working range (0.1 to 10.0 mu M), high recovery (96-103%) and low relative standard deviation (RSD = 3.2-4.7%) for DA and UA in real serum samples, possessing high significance for practical large-scale applications.

Automated summary

A bimetallic polycrystalline sensor (Cr/Fe-SNCM) with nanosized and high dispersion was developed for simultaneous electrochemical determination of dopamine (DA) and uric acid (UA). The sensor exhibited high graphitized carbon supporter and high electron transport and signal output due to the highly dispersed Cr/Fe sites and polycrystalline form. The sensor showed a lower limit of detection for DA and UA compared to state-of-the-art sensors, making it significant for practical large-scale applications.